A conventional apparatus for feeding sheets, booklets or the like as shown in FIG. 20 comprises an overlap feed limiting mechanism 2 provided in front of a stack loading section 1 on which a plurality of objects to be conveyed (printing paper, for example) are loaded in a vertically stacked state, and a feeding belt 3 provided below the stack loading section 1 and the overlap feed limiting mechanism 2. The feeding belt 3 is rotated so that the object extracted from the underside of the stack loading section 1 is fed through a gap between an overlap feed limiting member 4 provided at a lower end of the overlap feed limiting mechanism 2 and the feeding belt 3. In this case, adjustment of the overlap feed limiting mechanism 2 is executed so that the objects are fed one by one (or so that the objects are not fed in an overlapped state). For this purpose, the overlap feed limiting mechanism 2 is provided with a shaft insertion hole 5A formed through a fixed base 5 in the up-down direction and a moving shaft 6 inserted into the shaft insertion hole 5A. The moving shaft 6 has a lower end with which the overlap feed limiting member 4 is threadingly engaged, and the moving shaft 6 has an upper end with which an operating knob 7 is threadingly engaged. Furthermore, the moving shaft 6 includes a part exposed below the shaft insertion hole 5A, and a compression coil spring 8 is inserted into the outside of the part of the moving shaft 6 so as to be compressed between the overlap feed limiting member 4 and an upper end side open edge of the shaft insertion hole 5A. For example, when the object has a relatively larger thickness, the operating knob 7 is operated for a thread engagement advancing operation so that a gap (hereinafter, “nip gap”) between the overlap feed limiting member 4 and the feeding belt 3 is rendered larger. When the object has a relatively smaller thickness, the operating knob 7 is operated so that a thread engagement retreating operation is carried out thereby to render the nip gap smaller. Thus, the nip gap is adjusted so that the objects are fed one by one irrespective of the differences in the thickness thereof (refer to patent document 1, for example).